Selective landing of semiconducting single-wall carbon nanotubes onto tetrathiafulvalene moiety self-assembled on ITO substrate

Semiconducting single-wall carbon nanotubes (SWCNTs) were selecively interacted with tetrathiafulvalene (TTF) moiety self-assembled on indium tin oxide (ITO) substrate by charge-transfer interaction. The charge-transfer phenomena between two molecules were elucidated by cyclic voltammetry (CV) and Raman spectroscopy. CV measurement of TTF-modified ITO substrate as a working electrode presented the difference between heat-treated system and untreated one. The two redox potentials, which are typically related to redox behavior of TTF, were shown in the unheated system during both oxidation and reduction cycles, while the two oxidation peaks were disappeared in the heated system. Raman spectra indicated that the intensities of RBM originated from metallic SWCNTs were much reduced in the heat-treated system, while there were little change in the unheated one. These results revealed that only semiconducting SWNTs were selectively adsorbed on the TTF moiety self-assembled on ITO when the system with heat treatment.